Growth of Cyclotella meneghiniana Kutz .1. Effects of temperature, light and low rate of nutrient supply

A strain of Cyclotella meneghiniana was isolated from the River Danube. The optimum irradiance and temperature for growth were determined in batch cultures. The optimum temperature for growth was 25 degrees C. The estimated saturated irradiance was near 125 mu E m(-2) s(-1). The calculated I-k for growth and photosynthesis were 30 +/- 3 and 44 +/- 6 mu E m(-2) s(-1) respectively. A continuous culture technique was used to test the growth and cell composition at the transition state between batch, nutrient sufficiency, and a low rate of nutrient supply. Algal response was characterized by high intracellular N and C with negative growth rate. At a low dilution rate (0.06 d(-1)), the continuous culture theory was not followed. This critical rate is characterized by low chlorophyll-a content per cell and may depend on the mode of nutrition.